Human monoclonal antibodies block the binding of SARS-CoV-2 spike protein to angiotensin converting enzyme 2 receptor

Lilin Ye; Xiangyu Chen; Ren Li; Zhiwei Pan; Chunfeng Qian; Yang Yang; Renrong You; Jing Zhao; Leiqong Gao; Zhirong Li; Qizhao Huang; Lifan Xu; Jianfang Tang; Qin Tian; Wei Yao; Li Hu; Xiaofeng Yan; Xinyuan Zhou; Pinghuang Liu; Yuzhang Wu; Kai Deng; Zheng Zhang; Yaokai Chen; Zhaohui Qian

The copyright holder for this preprint (which was not peer-reviewed) is . https://doi.org/10.1101/2020.04.06.20055475 doi: medRxiv preprint states!of!S!protein!that!provide!very!limited!window!for!the!immunogenic!epitopes!of! RBD!exposure!to!specific!B!cells 20 .! Next,!we!set!out!to!clone!human!monoclonal!antibodies!using!the!blood!samples!from! three! COVID^19! recovered! patients,! of! which! their! sera! showed! potent! hACE2! receptor! binding! inhibition.! To! this! end,! we! sorted! each! SARS^CoV^2! RBD! specific,! IgG! class^switched! memory! B! cell! into! a! single! well! of! the! 96^well! microplates.! Subsequently,!we!used!reverse!transcription!polymerase!chain!reaction!(RT^PCR)!to! amplify!IgG!variable!heavy!chain!(VH)!and!light!chain!(VL)!from!each!single!memory!B! cell.! After! cloning! both! VH! and! VL,! we! inserted! both! sequences! into! expression! plasmids!that!encoding!constant!regions!of!human!IgG1!heavy!chain!and!light!chain!